Inactivation trends of Bacillus cereus and Listeria monocytogenes grown in tryptic soy broth to the early stationary phase and subjected to ultraviolet irradiation

• Published in: Han'guk Sikp'um Kwahakhoe Chi = Korean Journal of Food Science and Technology Vol. 54; no. 6; pp. 671 - 675
• Main Authors: Yoo, Hyorin, Kim, Sangoh, Kim, Sang-Soon
• Format: Journal Article
• Language: English
• Published: Seoul 한국식품과학회 31.12.2022; Korean Society of Food Science & Technology
• Subjects: Bacillus cereus; Deactivation; Deoxyribonucleic acid; DNA; Inactivation; Irradiation; Listeria; Listeria monocytogenes; Mathematical models; Pathogens; Shoulder; Stationary phase; Tailings; Trends; Ultraviolet radiation; UV radiation; Resistance; Listeria monocytogenes; Early stationary phase; Bacillus cereus
• ISSN: 0367-6293; 2383-9635
• DOI: 10.9721/KJFST.2022.54.6.671

In the present study, the inactivation trends of Bacillus cereus and Listeria monocytogenes, grown in tryptic soy broth to the early stationary phase and subjected to ultraviolet (UV)-C irradiation, were identified and analyzed using mathematical models. The inactivation curves of B. cereus showed a tailing effect and were best fitted with the double Weibull model. In contrast, the inactivation curves of L. monocytogenes showed both shoulder and tailing characteristics and were best fitted with the biphasic shoulder model. The survival of highly resistant pathogens along with non-uniform bactericidal treatment was suggested as the reason for the tailing effect; the multi-hit nature of UV irradiation along with the DNA recovery ability of the pathogens was suggested as the reason for the shoulder effect. Moreover, the pathogens grown to the early stationary phase were more resistant than those grown to the mid-stationary phase. Therefore, a wider range of studies is needed regarding pathogens growing to the early stationary phase.